Evidence suggests that 50-80% of persons with Multiple Sclerosis (PwMS) have difficulty walking and impaired balance, with half of them falling at least once a year. Falls can lead to increased risk of injury and fear of falling, which may further impair a person’s function. Studies have previously shown that patient-reported outcomes (PRO’s) predict PwMS’ risk of falling but small sample sizes and variable cut-off scores have limited generalization of the findings.
To determine the predictive value of a cut-off score for the 12-Item Multiple Sclerosis Walking Scale (MSWS-12) to identify PwMS with greater fall risk.
A total of 135 PwMS were included as part of a preliminary analysis of an ongoing, larger cross-sectional study in which the MSWS-12 and frequency of falls (self-reported over past 6 months) were collected. PwMS were designed as “faller” if they had >1 fall in the past 6 months. Descriptive statistics were used to describe the clinical characteristics of the fallers (n=82) and non-fallers (n=53) (age, gender, disease duration, use of assistance, and Patient Determined Disease Steps; PDDS). Clinical characteristics and MSWS-12 scores of the faller and non-faller groups were compared. A Receiver Operating Characteristic (ROC) curve was used to estimate the classification accuracy of the MSWS-12. Optimal cut-off scores were calculated using the Youden index and sensitivity and specificity were calculated.
There were no differences in age, gender, or disease duration between fallers and non-fallers. Fallers had higher median PDDS scores (3; 0-6 versus 1, 0-6; (p< 0.01)) and higher median MSWS-12 scores (67.5 versus 38.3; p<0.001) than non-fallers. Fallers were more dependent on assistive devices compared to non-fallers (p<0.01). The MSWS-12 cutoff score for fallers was ≥45.83 (Youden index: 0.46), with a sensitivity of 78.1%, specificity of 67.9% and a classification accuracy of 76.7% to detect fallers.
MSWS-12 was found to be predictive of fall risk in PwMS with a cut-off score much lower than previously reported. These findings indicate a lower threshold of the MSWS-12 score may help clinicians identify PwMS at greatest fall risk so that appropriate fall risk prevention interventions may be implemented.